I changed my filter floss yesterday and there were three worms trapped in it. I tried to free them with no luck. After going through the impeller, they got a little munched up and the remaining worm sections became totally entwined in the floss.

As a result, I will no longer use filter floss I just have a course sponge, which any worm would be able to get through just fine. Maybe the worms could just stay in the gravel? :P

be careful when touching those, the little hairs will release from the worm and into your skin and that hurts. I read somewhere that the hairs are designed to work their way deeper and deeper into your skin the more you move. I bumped one while aquascaping one time and started pulling the hairs with tweezers and they did not want to come out, they caused me pain for a few days.